• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.98-102
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• 2008

Methods and analysis of a simple wireless sensor concept for detecting and locating faults as well as for load monitoring are presented. The concept is based on distributed wireless sensors that are attached to the incoming and outgoing power lines of secondary substations. A sensor measures only phase current characteristics of the wire it is attached to, is not synchronized to other sensors and does not need configuration of triggering levels. The main novelty of the concept is in detecting and locating faults by combining power distribution network characteristics on system level with low power sampling methods for individual sensors. This concept enables the sensor design to be simple, energy efficient and thus applicable in new installations and for retrofit purposes in both overhead and underground electrical distribution systems.

• 분석과학
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• 제22권6호
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• pp.439-448
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• 2009

• 한국전자파학회논문지
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• 제14권5호
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• pp.437-443
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• 2003

정밀 전기.전자기기들이 외부의 전원장해와 과도 전압에 의하여 오동작되거나 부품이 파괴되어 기기의 기억장치가 지워지기도 하며, 전도성 노이즈의 형태로 다른 기기에 장해원이 될 수도 있는 등 그 피해가 늘고 있어 이에 대한 보호대책이 요구되고 있다. 따라서 본 논문에서는 디지털 영상기기인 PDP를 측정대상기기(EUT)로 하여 임피던스에 적합한 노이즈 저감 필터를 제작하고, 더불어 관통형(Feed-through) 커패시터 와 높은 투자율을 가진 페라이트 비드로 이루어 진 필터를 함께 적용한 PDP용 광대역 EMC 필터를 제작하고, 그 특성을 평가하였다. 본 연구에서 제작한 필터의 삽입손실은 10 MHz~l.5 GHz에서 40 dB 이상 감쇠되어 CISPR Pub. 22규격과 IEC 61000-4-4의 level 4까지 만족하는 우수한 필터임을 확인하였다.

• 조명전기설비학회논문지
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• 제19권4호
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• pp.91-97
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• 2005

산업화로 인버터, 컨버터, 스위칭 전원공급기, 모터와 같은 비선형 장치들이 늘어가고 있다. 그러나 컴퓨터와 전기장치 등과 같은 전력품질에 민감한 부하의 사용이 빠르게 확산되어 왔다. 게다가 전력품질 문제와 실시간 전력품질 모니터링은 산업과 빌딩에서 시스템의 지능제어로써 관심이 증대되고 있는 문제 중에 하나이다. 그중 하나인 전력선통신을 이용한 전력품질 모니터링 시스템은 새로운 선로가 없이도 전력품질 정보를 보내고 받을 수 있는 큰 장점을 가지고 있다. 본 논문에서는 IEEE Std. 1159의 분류에 따라 전력품질 문제를 측정하는 알고리즘의 개발과 보드를 제작하고 이를 전력선통신을 이용하여 모니터링하는 시스템을 구현하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집
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• pp.6-7
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• 2008

The purpose of this study was to investigate heat resistance for union type SMD inductor core. The samples was produced with process 5 step. In this study, it analysis heat resistance of SMD(Surface Mounted Device) inductor core and it get electric field only exist inside of SMD core. Therefore electric fields do not affect any device and equipments. These results are very important to design data acquisition system(several test equipments such as temperature, impedance, and current test), because data acquisition system can place under the SMD Inductor core. So, it can be decrease their test error due to electric field.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.87-87
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• 2010

Epoxy/mica has been used as the material of high-voltage rotator stator winding due to its high insulation performance, mechanical strength, and thermal stability. In recent years, however, it shows frequent changes in the load of generators and frequent automatic stops due to the significant increase in peak loads from the increase in the applied load of power facilities according to the introduction of advanced and high-technology equipments. Thus, it is necessary to develop new materials that highly develop the conventional insulation materials. Nanotechnology introduced in the present time has become an alternative plan that overcomes such technical limitations. In addition, the nano-scaled intercalation composite has been known as the material that represent excellent electrical, mechanical, and thermal characteristics compared to the conventional materials. This study investigated the dielectric dispersion and relaxation characteristics of the nanocomposite, which was fabricated by mixing epoxy matrix with nano-scaled intercalation mica and clay, according to changes in frequencies and temperatures.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.103-105
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• 2008

In, this paper, we consider the relation between on-line monitoring and diagnostics on the one hand and high-voltage (HV) withstand and partial discharge (PO) on-site testing on the other. HV testing supplies the basic data (fingerprints) for diagnostics. In case of warnings by on-line diagnostic systems, off-line withstand and PO testing delivers the best possible information about defects and enables the classification of the risk. Because alternating voltage (AC) is the most important test voltage, the AC generation on site is considered. Frequency tuned resonant (ACRF) test systems are best adapted to on-site conditions. They can be simply combined with PO measuring equipment. The available ACRF test systems and their application to electric power equipment -from cable systems to power transformers - is described.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.451-455
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• 1997

The partial discharge has been blown as the chief breakdown of power equipments. The analysis and the recognition is much difficult because the partial discharge signal is very small and has complex aging pattern. Recently, insulation aging diagnosis based on pattern of phase(Ф), partial discharge magnitude(q), number(n) has been very important. Owing to depreciate the reappearance of aging progress at the electrical tree pattern and to be difficult to analyze visually, the study on partial discharge pattern is suggested to normalizing analysis method of partial discharge signals. This parer is purposed on prediction of life-time measurement of cv-cable, on decision of risk degree with normalization and real-time measurement of partial discharge signals for aging diagnosis of cv-cable. As normalizing the aging signals of electrical tree in cv-cable, it is able to confirm risk degree of insulation material with the distribution of Ф-q-n and recognize the process of aging pattern using neural network.

• 전기학회논문지
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• 제56권4호
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• pp.705-715
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• 2007

Recently, the interest on power quality has been hot issue because the equipments cause voltage disturbance and have become more sensitive to the voltage disturbance. Additionally, the reseach on power electronic equipments applying to the high power has been increased. This paper deals with Line-Interactive Dynamic Voltage Restorer(LIDVR) system using 7-Level H-Bridge inverter, which is one of the solutions to compensate the voltage disturbance and to increase the power of equipments. The LIDVR has the following advantages comparing to the DVR with the series injection transformer. It has the power factor near to unity under the condition of normal source voltage, can compensate the harmonic current of the load and the instant interruption, and has the fast response. First, the construction, the operation mode and algebraic modeling of LIDVR are reviewed. And then the voltage control algorithm is proposed to get the sinusoidal load voltage with constant amplitude. Finally, simulation and experiment results verify the proposed LIDVR system.

• 조명전기설비학회논문지
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• 제20권2호
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• pp.60-67
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• 2006

이 논문은 서지보호기의 설치조건에 따른 보호효과에 대하여 기술하였으며, 뇌서지로부터 정보통신설비를 효과적으로 보호하는 설치기법을 제안하기 위해 서지보호기의 보호효과에 미치는 설치위치, 분기회로의 길이, 배선방법, 전선관 재료의 영향에 대해서 실규모 조건에서의 실험을 수행하였다. 그 결과, 보호하고자 하는 각각의 전자기기의 입력단에 서지보호기를 설치하는 것이 효과적이며, 선간에 서지보호기를 설치할 때는 접속선의 길이가 최소가 되도록 하는 배선방법이 효과적이다.